With development of touch control technology, more and more mobile terminals perform a human-machine interaction in a touch control manner. Besides finger contact, the touch display screen may use touch pen contact to perform operations.
A touch pen comprises a passive pen and an active pen. The passive pen is functionally equivalent to a finger. When using the passive pen to contact the touch display screen, one small fraction of current will flow into the passive pen from the touch display screen via a touch point, which is equivalent to a change in an electrode capacitance at the touch point. A control chip of the touch display screen may determine the position of the touch point by detecting the change in the electrode capacitance at the touch point. Generally, the nib of the passive pen is designed to be relatively large. In contrast, the active pen may emit an excitation signal to change an electric field at the touch point, thereby changing the electrode capacitance at the touch point. The control chip of the touch display screen may determine the position of the touch point by detecting the change in the electrode capacitance at the touch point. The nib of the active pen may be designed to be relatively small.
One technical drawback of an existing active pen is that it may not sense the operating force of a user, thereby possibly causing a great deviation between operation inputs of the user and display outputs of the touch display screen, thus resulting in relatively low accuracy of the human-machine interaction. For example, when a user writes words with the existing active pen, handwritings displayed by the touch display screen are consistent in weights, this largely deviates from actual input handwritings of the user, thereby causing poor writing effect and being adverse to finger-writing recognition.